Ecosystem - Living beings and non living beings, web

Ecosystem

1. unit - 1 Definition Natural Resources Ecosystem

2. Definition: Ecosystem or biocenosis, Mobices (1877) is a structural and functional unit of biosphere consisting of living organisms and the physical environment both interacting with each other. The term was introduced by Tansley (1935).

3. Any distinct community of its own forms an ecosystem e.g. rotting log, pond, lake, river, orchard, park, forest etc. Besides this, an ecosystem commonly posses two types of organisms- Autotrophs and Heterotrophs

4. Autotrophs. Photosynthetic organisms which manufacture their own food from raw material land energy from the sun. Ex: Producers – Plants.

5. Heterotrophs. These organisms are dependent on autotrophs for their survival as they cannot manufacture food on their own. Depending upon the source of organic food, heterotrophs are: herbivores, carnivores, detrivores (dead – organic matter feeders), Consumers & decomposers.

6. Structure of an Ecosystem: Major components of an ecosystem are I. Biotic II. Abiotic.

7. Flow Chart for the structure of an Ecosystem

8. All Green plants are called producers. They produce carbohydrates by photosynthesis and also synthesize proteins and fats. Producers are also called transducers as they are able to change radiant energy to chemical form. Producers:

9. All the other organisms (heterotrophs) depend upon producers for their survival. Besides this producers also maintain CO2/O2 balance of nature. Consumers. The animals which consumes energy produced by producers as food are called consumers.

10. They are also called phagotrophs. Consumers are differentiated into two categories - 1. herbivores 2. carnivores.

11. Herbivores. These are called first order consumers which obtain their food directly from plants. (i) Terrestrial herbivores. Deer, rabbit, mouse, goat cattle etc. (ii) Aquatic herbivores. Crustaceans, mollusks, protozoans.

12. (b) Carnivores . Carnivores prey upon other animals. They have been classified as ( i ) Primary Carnivores/Third Order Consumers. They prey upon primary carnivores e.g frog, birds, fishes, jackal, fox, snakes. (ii) Secondary Carnivores/Third Oder Consumers . Carnivores e.g. owl, peacock, lion, tiger etc. Carnivores like lion, tiger etc. which cannot be preyed upon further are called top carnivores and their number is considerably low.

13. The non-green organisms like fungi and bacteria which are incapable of producing their own food living on dead and decaying plants or animal parts and are consumers of a special kind are called decomposers. Detrivores or Scavengers. Animals which feed on dead bodies of other organisms e.g. termites, carrion buttes. They are helpful in quick disposal of the dead bodies. Decomposers :

14. These are the non - living components of an ecosystem. They are of two forms: (i) Climatic. Temperature, humidity, precipitation, light etc. (ii) Edaphic. Topography, pH, minerals, back-ground. Abiotic Components :